Treatment in gas distribution systems



TREATMENT IN GAS DISTRIBUTION SYSTEM Filed June 10, 1939 fgi Patented Apr. 6, 1943 TREATMENT IN GAS DISTRIBUTION SYSTEMS John R. Skeen, Philadelphia, P8., assignor to The United Gas Improvement Company, a corporation of Pennsylvania Application June 10, 1939, Serial No. 278,499

9 Claims. (Cl. 48-190) This application is a continuation-in-part of my copending application Serial Number 236,822, filed October 24, 1938, and pertains generally to the treatment of the interiors oi gas mains or other gas enclosures for the purpose of sealing joints or laying dust, or both.

Systems for the distribution of gas include conduits or mains which are usually laid underground, and which comprise sections of pipe joined together by means of welding, by means of packed joints, by means of screw joints, or otherwise.

The welded joint is a more recent development and is used chiefly to join pipe sections of steel or iron, other than cast iron.

Older mains are usually made up of cast iron pipe sections joined by means of bell and spigot or other similar joints. These joints are usually packed with hemp, jute, flax Or other cellulosic material which in turn is backed up with lead or cement or other material in a well known manner.

The lead or cement seal is tight and effective in preventing gas leakage when first applied but soon loses this quality due to expansion and contraction of the main with change in temperature or for other reasons. When this happens the effectiveness of the joint in preventing gas leakage depends entirely upon the packing.

Generally speaking, there are two types of cellulosic packing or yarn which have been used in joints of gas mains or other gas enclosures.

At the time of their insertion in the joint, packing materials may be classified as absorbent and non-absorbent in that the capacity of the former to absorb water has not been impaired by special treatment, whereas such capacity of the latter has been purposely removed such as by treatment with tar.

These widely different types of packing may be referred to as "untarred and tarred" respectively, and have widely different characteristics in service. For instance. the untarred type of packing is capable of absorbing water which in turn swells the packing. This capacity continues until partially or wholly impaired by the accumulation of tar, resin and gum formed from constituents in the gas. the tar. resin and gum coating the packing. When this occurs the capacity of the packing to take up and give oil moisture with change in gas humidity is considerably reduced and the packing takes on the characteristics 0! the tarred type.

Until recently, when high pressure distribution has come into more general practice, the bell and spigot or other joint packed with the untarred type of packing gave very little trouble since the gas generally contained sufilcient moisture to keep the packing saturated and, therefore, gastight.

However, when the gas is compressed to a high pressure for long distance distribution in welded mains before being expanded to low pressure for local distribution, most of the water vapor (and some of the oils) are condensed out. There is then no longer suflicient water vapor in the gas when expanded to the low pressure to keep the fibrous packing in the packed Joints in the low pressure mains moist. On the contrary, the gas is so dry that it rapidly draws out any absorbed moisture in the packing at a rate depending somewhat upon the accumulation of tar, resin and gum. However, the packing eventually dries out since the accumulation of tar, resin and gum.

is rarely capable of sealing moisture in the fibres.

It follows that when the packing dries out serious 1 leaks occur.

In other Words, as long as the main is used for distributing ordinary manufactured gas, and assuming that the untarred type of packing was originally installed, very little trouble with joint stance, and consequent drying and shrinking should the moisture content of the gas be lowcred, nevertheless, the tarred type of packing has not been wholly successful. This is thought to be due in part to shrinkage in volume or cracking of the tar due to drying or polymerization, and also in part to the necessity of swelling a packing in a joint to cause the packing to conform more exactly to the contour of the Joint and to reduce voids between the fibres,

Soap is sometimes applied to the untarred type of packing. Such treatment, however, does not prevent drying and shrinking.

Referring now to the problem of dust, it is to be noted that over a period of years the water condensed from wet gas together with other constituents 01 the gas such as carbon dioxide, hydrogen sulfide, hydrocyanic acid, naphthalene, and so forth, have in many instances, caused extensive corrosion of the interior walls of the: mains. The products of corrosion have accumulated on the wallsof the mains and, in many instances, large quantities have become disconnected and have collected along the bottom.

Due to the presence of relatively large quantities of moisture, largely responsible for the corrosion in the first instance, the products of corrosion were maintained in a wet condition and did not tend to form dust in any appreciable quantity.

Therefore, until high pressure distribution came into practice, and while the use of natural gas or natural gas mixtures was less widespread, very little difliculty was experienced with the formation of dust in mains from the products of corrosion.

In other words, as long as a main is used for distributing ordinary wet manufactured gas very little trouble with dust. resulting from corrosion is experienced. However, when the service is changed over to a manufactured gas of low moisture content, or over to natural gas or natural gas mixtures which are characterized by very low moisture content, the moisture on and in the corrosion products dries out and such products become a serious source of dust.

The presence of considerable quantities of dust in the gas flowing through the mains 01 a distribution system is very undesirable because dust tends to clog up customer service connections, interferes with the proper operation of meters, and tends to clog up burners and pilot outlets.

Under extreme conditions corrosion may be so severe as to form a serious obstruction'in the main itself by reducing its effective cross-sectional area such as by the accumulation of dust in piles in the main.

Since the corrosion products comprise not only ordinary iron rust but also a variety of other compounds resulting from the action of hydrogen sulfide, hydrocyanic acid, naphthalene, and other corrosive substances, the problem of wetting down the dust, or wetting the main wall, and of thoroughly spreading a dust laying liquid becomes a major factor.

While the water miscible high boiling alcohols and water miscible organic oils are generally suitable for the purpose of laying dust as described and claimed in copendlng applications Serial Number 167,316, filed October 4, 1937 and Serial Number 208,729, filed May 18,, 1938, both by Duncan B. Williams, which have matured into Patents 2.167140 and 2.l6'7,141 respectively, only three of the substances specifically set forth in said applications are capable of swelling cellulosic fibre packing to the same extent as water. With dry jute the volume increase caused by the swelling is 44%.

I have discovered two additional substances namely, monomethyl ether of ethylene glycol and monomethyl ether of diethylene glycol which are capable of swelling cellulosic fibre packing sufficiently to prevent joint leakage as described and claimed in my copending application Serial Number 128,555 filed March 1, 1937, now Patent 2,141,959 issued Dec. 2'1, 1938.

The percentage swelling of dry jute by a number of liquids is set forth in Tables 1 to 3:

TABLE 1 Substance Swelling Per cent Ethylene glycol 44 Diethylene glycol 44 Monomethyl ether of ethylene glycol. 38 Monomethyl ether of diethylene glycol 44 Glycerine 44 TABLE 2 Substance I Swelling Per cent Monobutyl ether of ethylene glyco o M onobutyl ether of diethylene lyeol 0 Monophenyl ether of ethylene g ycol 0 Triethylenc glycol. 1 Monoethyl ether of triethylene glycol 2 Monomethyl amyl ether of ethylene glycol 4 M onoethyl ether of diethylene glycol l6 Monoethyl ether of ethylene glycol 10 TABLE 3 Substance Swelling Per cent Mixed tar bases 0 Hexone 3 Quinolin 4 Octyl aldehyd g Deeane 8 Triethyl benzene. 9 Octyl alcoh 11 Olive oil 13 S indie oil.. 14 Benzaldehyde 0 Oleic acid 3 Benzyl alcohol n 0 Dimethyl cyclic hexanol. 0 Amyl acetate 4 Diethyl (I Decahy o naphthalene l3 Ethylene diamine D s ntegrates Pyridine Disintegrates Aniline Disintegrates A'number of liquids suitable for dust laying are set forth in Table 4.

TABLE- 4 Non-cyclic high boiling aliphatic alcohols:

It should be noted that Table 4 includes not only the liquids of Table l which alone are suitable for swelling joint packing, but also liquids of Table 2 as well as others which in themselves are not suitable for swelling joint packing.

All of the substances listed in Table 1 are of relatively low vapor pressure compared to water and are relatively inert in the presence of the gas. Each of them except glycerine is rapidly absorbed by uncoated packing. Highly concentrated glycerine has a viscosity which is somewhat too high for rapid absorption by the packing. This quality, however, may be greatly improved as will hereinafter appear.

Likewise, all of the substances of Table 4 are of low vapor pressure compared to water and are relatively inert in the presence of the gas.

In many distribution systems tar, resin, gum, and dust have been deposited upon the packing and operate to exclude the substances listed in Table 1 from contact with the packing. In the case of packing which was originally tarred these substances, of course, are also excluded from contact with the Packing. The substances of Table l are rather deficient as softening or solubilizing agents for tar, resin and gum.

The tar, resin, and gum likewise prevent the materials of Table ifrom reaching and wetting active sources and potential sources of dust, these materials being likewise for the most part deficient as softening or solubilizing agents.

A feature of this invention is to provide an improved leak proofing composition for swellin cellulosic packing in jointsof gas distribution systems which possesses sufilcient solvent power with respect to tar, resin and gum to cause the swelling constituents of the composition to be absorbed by the packing with sufficient rapidity for practicable purposes.

Another feature of the invention is to provide an improved dust laying composition which possesses suflicient solvent power with respect to tar, resin and gum to cause the dust laying constitu-, ents of the composition to wet dust sources and to wet and be absorbed by accumulations of dust with suflicient rapidity for practicable purposes.

Another feature of the invention is to provide a joint sealing and/or dust laying composition having improved wetting qualities not only for tar. resin and gum, but also for cellulosic fibre and the metal of the main walls.

Another feature of the invention is to provide a new article of manufacture and a process for making the same. e

Other features of the invention will become more apparent to persons skilled in the art as the specification proceeds.

Generally speaking, the improvement in leak proofing compositions comprises two o more mutually miscible liquids, one of which is especially adapted to be absorbed by the packing and to swell the packing to at least substantially the same extent as water; and the other of which is especially adapted a) to soften or dissolve tar, resin and/or gum which may cover the packing,

a and (b) to assist the spreading and climbing of the swelling agent in the joint packing. In the event that these two or more liquids are not in themselves mutually miscible in the quantities employed, a miscibility agent may be added. Such agent may comprise a liquid solvent in which the two or more liquids employed are soluble.

Example of the first mentioned liquid of the leak proofing composition comprise any one or more of the substances listed in Table 1. such substances being mutually miscible with each other.

Examples oi the second mentioned liquid of the lmlk roofing composition omprise one or more of the following group of substances and mixtures containing the same.

(1) Ketones generally and particularly liquid ketones. V

Aromatic ketones such as acetophenone, benzophenone and orthohydroxyacetophenone are especially effective. The liquid ketones are preferred. Other aromatic ketones are meta and para hydroxyphenone, tetramethyldiaminobenzophenone (Michlers ketone), tetr'aethyldiaminobenzophenone, phenyltolyl ketone, etc., many of which are solid at ordinary temperatures.

Liquid aliphatic ketones which are especially effective are acetone, diacetone alcohol and mesityl oxide. Other aliphatic ketones are methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl n-butyl ketone, ethyl n-propyl ketone, methyl isobutyl ketone, ethyl isopropyl ketone, methyl sec-butyl ketone, methyl tert-butyl ketone, methyl n-amyl ketone, dipropyl ketone, diisopropyl ketone, hexamethylacetone, and methyl neopentyl ketone.

An example of a liquid alicyclic ketone is 0% clohexanone.

Ketones of higher molecular weight than those of the above examples ma be employed, if desired, especially if they are unsaturated and contain more than one ketone group.

Examples of miscibility agents suitable for incorporation in leak proofing composition to insure a single liquid phase are:

Phenyl cellosolve monophenyl ether of ethylene glycol) Acetone Diacetone alcohol Mesityl oxide Phenyl carbitol (monophenyl ether of diethylene lycol) Reference is made to my copending'application Serial Number 285,942, filed July 22, 1939, in which the employment of main treatirig'iiquid mixtures containing a non-cyclic high boiling aliphatic alcohol and monophenyl ether of ethylene glycol (phenyl cellosolve) is described and claimed.

Referring now to dust laying compositions, generally stated, the improvement comprises two or more mutually miscible liquids one of which is adapted to wet, hold and/or bind dust particles and to coat dust sources: and the other of which is adapted o) to soften or dissolve tar, resin and/or gum which may cover dust sources or form incrustations with dust deposits and (b) to assist the spreading and climbing of the dust laying liquid upon th walls of the gas main and throughout the sources of dust. In the event that these two or more liquids are not in themselves mutually miscible in the quantities employed, a miscibility agent may be added. Such agent may comprise a liquid solvent in which the two or more liquids employed are soluble.

Examples of the first mentioned liquid of the dust laying composition comprise any one or mor of the substances listed in Table 4.

Examples of the second mentioned liquid of the dust laying composition are the ketones, their homologues and mixtures listed above in connection with the leak proofing composition.

Examples of miscibility agents suitable for intreme casessuch as tarred type, or larg quantities of tar, resin Methyl carbitol Butyl carbltol Phenyl cellosolve Acetone Diacetone Mesityl oxide Phenyl carbitol Any desired quantity of my tar, resin and/or gum softening and/or solubllizing and wetting agent (referred to hereinafter and in the claims for convenience as tar penetrating agent) may be addedto the fibre swelling and/ or dust laying liquid. I find, for example, that for ordinary purposes from to 20% is sufficient, but in exwhen the packing is of the and/or gum have deposited from the gas that much larger quantities are preferably employed, for example up to say 70% or more.

Furthermore, the more drastic treatment or treatments may be followed by a less drastic treatment or treatments, such as the treatment for ordinary purposes.

Moreover, the main may be treated first with the tar penetrating agent and then with the dust laying and/ or joint sealing agent without departing from the spirit of the invention. 7

The presence of my tar penetrating agent greatly increases the distribution of the treating liquid and its penetration through tax, resin, gum and dust incrustations'and, therefore, not only greatly decreases the time of treatment, but also greatly increases the-thoroughness and effectiveness of the treatment when tar, resin, gum and/or dust incrustations are present.

I find that my tar penetrating agents do not interfere with the functions of the other ingredients of the composition, and greatly enhance the spreading and climbing of the same.

Although the ketones are not of a particularly corrosive character, if desired, a suitable corrosion inhibitor, such as triethanolamine might be added of which amounts from 0.5 to 1.5% are examples.

Examples of liquid mixtures for both leak proofing and dust laying are as follows:

The latter composition is rapidly absorbed by the cellulosic packing, whereas, when glycerine alone is used the rate of absorption is rather slow.

It is to be noted that in the case of high viscosity liquids such as glycerine, my tar penetrating agents also serve to reduce the viscosity thus reducing the time required for the composition to flow through the main when applied in this man- 1 excessive the following are more suitable in view of the increased concentration of the tar penetrating agent in th mixture.

Example 4 7 Per cent Glycerine 30 Orthohydroxyacetophenone '76 Example 5 Diethylene glycol 10 Monomethyl ether of diethylene glycol 20 Benzophenone 35 Orthohydroxyacetophenone 33 Triethanolamine 2 Example o Glycerine- 30 Acetophenone 68 Triethanolamine 2 Example 7 Diethylene glycol 30 Mesityl oxide 34 Diacetone alcohol 34 'Iriethanolamine 2 Example 8 Diethylene glycol 30 Mesityl oxide 22 Acetone 22 Orthohydroxyacetophenone 24 Triethanolamine 2 Example 9 Diethylene glycol 15 Monomethyl ether of diethylene glycol 35 Cyclohexanone 15 Acetone l5 Benzophenone 18.5 Triethanolamine 1.5

Generally speaking, any other liquid or combination of liquids of Table i may be substituted for diethylene glycol or glycerlne in the above examples and any other ketone or any combination of ketones may be substituted, preferably using a miscibility agent when necessary to form a single liquid phase, which is preferred to a plurality of liquid phases, although it is conceivable that the latter may be employed without departing from the broad concept of the invention.

Examples of liquid mixtures suited more particularly for dust laying only are as follows:

Example 1 I Per cent Orthohydroxyacetophenone Monophenyl ether of ethylene glycol 50 Diethylene glycol 30 Example 2 Benzophenone 15 Dibutyl phthalate '75 Monomethyl ether of diethylene glycol 10 Example 3 Orthohydroxyacetophenone 15 Diacetone alcohol 5 Propylene glycol Monobutyl ether of diethylene glycol Example 4 Generally speaking, any other liquid or combination of liquids of Table 4 may be substituted for the dust laying liquid or liquids in the above examples. Likewise, any other ketone or any combination of ketones may be substituted, preferably using a miscibility agent or other means such asforming an emulsion when necessary to i'orm a single liquid phase, which is preierred to a plurality of liquid phases, although it is conceivable that the latter may be employed without departing from the broad concept of the invention.

The treating liquid may be applied to the interior surface or a pipe section and/or to the packing in a joint'before, during or after the assembly of the pipe sections to form the main. This may be accomplished in any. desired manner such as by dipping, spraying, brushing, or otherwise.

I! the main is already in service, sections of the main may be blocked oil" by means of inlisted bags or other means, and the sections then completely filled with the liquid after which the liquid can be drawn and re-used.

0n the other hand, the liquid may be sprayed into the gas by the logging procedure earlier 40 mentioned so that the packing and/or dust sources absorb the liquid from the gas stream or, in other words, so that the liquid is deposited from the gas stream onto the packingand/or onto the sources of dust.

In another method 01 application the liquid is introduced into the main at high points and allowed to run by gravity to low points where the excess can be drawn oil. An examination of mains treated in this manner shows that my compositions have greatly improved climbingproperties.

Another method comprises inserting a long length of hose into the main with a spray at its end pr with a plurality of sprays distributed don tilts length, and pumping the treating liquid {moths hose while withdrawing the hose either continuously or intermittently or otherwise, 9; while the hose remains stationary.

In the last three methods of application service on the line need not be interrupted. The packing becomes impregnated with the composition and dust sources become coated with the treating liquid. The wetting of finely divided material causes it to be bound together in a mass which prevents it from rising in, a dust regardless of the velocity of the gas traveling through the main. The clogging of mains, meters, regulators and appliance is thus effectively prevented.

A typical gas main is illustrated in the drawing in which:

Figure 1 is a side elevation, partly in section, illustrating a gas main; and

Figure 2 is a cross-section on line 2-4 of Figure 1.

In the drawing the gas main II is shown with a Joint comprising bell II and spigot i2 fitting within said bell and spaced therefrom. In the space between the bell and the spigot is cellulosic fibre packing I! which may be tarred or untarred and a seal l4 0! lead or other suitable material for holding the packing in place. The treating liquid as illustrated is being run through the main by gravity. It contacts the bottom of the main and any deposits accumulated thereon. It also contacts the packing at space I which space is leit'between the spigot and the shoulder of the bell to provide for expansion and contraction due to temperature changes. The packing absorbs the liquid at I8 and the liquid climbs and is carried up in the packing as shown by the outer group of arrows in Figure 2. It a substance of Table 1 is present the packing is swollen'to substantially the same extent as with water. The treating liquid also climbs up the metal walls of the main as illustrated by the inner group of arrows in Figure 2' to coat dust sources in addition to those along the bottom of the main.

The bulk of the treating liquid, of course, remains in the main only during the time that its flow from the point of introduction to the point I of removal which usually is the nearest drip.

Any other means for appl ing the treating liquid to the packing and/or to the interior of the conduit may be employed. For instance, in the case of very large diameter mains the level of the liquid l5 may be raised or may be made to 1111 the entire main if desired, or the spray or fogging methods may be employed.

In the case of a welded main, or other main having Joints in which ceilulosic fibre packing is not present, the treatment becomes primarily one of dust laying. Likewise, when the liquids of Table 4 other than those of Table 1 are employed the treatment becomes more essentially one of dust laying regardless of the type of main treated.

While the invention has been described in connection with gas mains it is to be understood that it is applicable to any part of a gas distribution system wherein similar problems may arise. It

' is also to be understood that the various agents referred to herein may be used either in the pure or commercially pure form, or in any other suitable form including the commercial and crude i'orms.

The terms comprising and "comprises are used; in the claims in their usually accepted meanings which do not exclude other steps or the presence of substances other than those specifically recited.

It is to be understood that the above particular description is by wayot illustration and that changes, omissions, additions, substitutions, and/0r modifications might be made within the scope of the claims without departing from the spirit of the invention.

I claim:

1. A method for treating the interior or a gas packing with a celiulosic fiber swelling agent selected from a group consisting oi ethylene glycol,

diethylene glycol, mononiethyl ether of ethylene glycol, monomcthyl ether of diethylene glycol, and glycerine by bringing said agent into contact with sa d packing in the presence of one of a group consisting of acetophenone, benzophenone, orthohydroxyacetophenone, acetone, diacctone alcohol, and mesityl oxide.

3. A method for laying dust in the interior of a gas distribution conduit having, dust deposits along the bottom thereof, comprising enveloping said dust dcposits'with a dust laying liquid selected from a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol. and glyccrine by bringing said liquid into contact with said dust sources inthe presence of one of a group consisting of acetophenone, benzophenone, orthohydroxyacetophenone, acetone, diacetone alcohol, and mesityl oxide.

4. In a method for reducing gas leakage through fibrous packing such as jute and hemp in a joint of a gas conduit, the step of impregnating said fibrous packing while in place in said joint with a liquid mixture comprising one of a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol, and glycerine and one of a group consisting of acetophenone,benzophenone, orthohydroxyacetophenone, acetone, diacetone alcohol and mesityl' oxide,

5. A joint in a gas distribution system comprising spaced cooperating elements, cellulosic fibrous packing such as jute and hemp between said cooperating elements positioned to form a seal and a liquid mixture absorbed by said packing, said liquid mixture comprising at least one of a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomcthyl ether of diethylene glycol, and glycerine and at least one of a group consisting of acetophenone, benzophenone, orthohydroxyacetophenone, acetone, diacetone alcohol and mesityl oxide.

6. A joint in a gas distribution system comprising. a bell, a spigot positioned Within and spaced from said bell to form an annular space, an annular ring of cellulosic fibrous packing in said annular space and continuously contacting said bell and, spigot on its outer and inner peripheries respectively, and a liquid mixtureabsorbed by said packing, said liquid mixture com prising at least one of a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomcthyl ether of diethyb ene glycol, and glycerine and at least one of a group consisting of acetophenone, benzophenone, orthohydroxyacetophenone, acetone, diacetone alcohol, and mesityl oxide.

7. A method for treating the interior of a gas distribution system which comprises applying to the interior of said system a liquid mixture comprising a non-cyclic high boiling aliphatic alcohol, and a ketone.

8. A gas conduit having interior dust sources wetted' down with a liquid mixture comprising a non-cyclic high boiling aliphatic alcohol, and a ketone.

9. A joint in a gas distribution system comprising spaced cooperating elements, cellulosic fibrous packing such as jute and hemp between said cooperating elements positioned to form a seal, and a liquid mixture absorbed by said packing, said liquid mixture comprising a ketone, and at least one of a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol, and glycerine.

JOHN R. SKEEN. 

